Heat treatment of metals



Patented Jan. 7, 1930 UNITED STATES PATENT OFFICE ALBERT a. SOMERVILLE,- or rnusnme, NEW YORK, ASSIGNOR or TWO-THIRDS To B. T. VANDERBILT courANY, iNconronA'rnnor NEW YORK, N.. Y., A CORPORA- TION OF NEW YORK No Drawing.

This invention relates to improvements in the heat treatment of metals and includes improved heat treatment baths and also 1mprovements in the method of heat treatment 5 of the metals.

More particularly, the invention'relates to improvement in oil baths for the heat treatment of metals and the heat treatment of the metals therewith.

When oil baths are used for tempering or heat treating metals and alloys, the bath may be maintained at hi h temperatures for prolonged periods of tlme with resulting tendency of the oil baths to change in composltion and to deteriorate.

According to the present invention, the 011 baths have combined therewith a stabilizing ingredient, or stabilizing ingredients, whereby the deterioration of the oil composition is revented or reduced or its rate of deterioration more or less regulated and controlled so that it will have improved stability and resistance to objectionable deterioration. According to the present invention, I add 2 to and incorporate with the oil bat-h used for the tempering or the heat treatment of the metal, a small amount of a condensation product of a carbonyl derivative (aldehydes or ketones) with a nitrogenous base such as 3 ammonia and amines, which condensation product serves as a stabilizin agent to retard or prevent or regulate ob ectionable deterioration of the composition.

The oil compositions which are employed in the present invention include oil compositions such as are commonly used for oil baths in tempering and heat treatment of metal.

The oil baths may be, for example, such as are employed to heat metals up to the proper 4 temperature, for example, a temperature of around 500 F, or they may be oil compositions such as are used for quenching heated -metals in which case the temperature of the bath may be kept at or below 100 F, or at 4 a regulated higher temperature, except for local overheating caused when the highl heated metal is introduced into the oil bath.- For the latter purpose, mineral oils, animal oils, vegetable oils, and mixtures of these are used, cotton seed oil being a-preiterred oil Application filed July 15,

HEAT TREATMENT OF METALS 1926. Serial N0. 122,729.

among the fatty oils, because of the tendency of oils like linseed oil to become gummy and of the animal and fish oils to become rancid or give ofi oflensive odors. The invention is of particular value with mineral oils, or mixtures containing mineral oils, suitable for use for tempering or heat treatment of metals.

According to the present invention, such tempering or heat treatment oil composi-' tions or baths have incorporated therewith a small amount of a condensation product of an aldehyde or ketone with a nitrogenous base. The condensation product should be soluble or miscible with the oils sothey are intimately distributed throughout the composition. They may be added directly to the composition orito certain ingredients of the composition, or they may be first dissolved in a solvent such as benzol and added in that form with subsequent heating of the mixture to remove the benzol.

The amount of the condensation product which it is necessary to add is small. In general, a few percent at most will suffice, and as little as a fraction of a suficient, e. g., 0.5% to 1%. The invention will be further illustrated by percent may be the following specific examples, but it is intended and will be understood that the invention is illustrated thereby but is not limited thereto.

A mineral oil composition of a consistency and character suitable for use for tempering or heat treatment of metals, has added thereto about 1% of acondensation product of acety ties when used as a tempering or heat treatment bath.

Ina similar manner, a mixed mineral oil and vegetable oihcomposition (e. g. containlng cotton seed oil) may have added thereto a small amount, for example, to 2%, of the condensation product above referred to.

In a similar manner, other tempering or heat treatment oil baths may have a small amount of one or another of the condensation product added thereto and incorporated therewith, thus imparting to the composition improved stability and resistance to deterioration. Y v

Instead of using the condensation product of acetaldehyde and aniline, the condensation product of aldol and alpha-naphthylamine can be similarly 'used, or other condensation products of aldehydes, such as: formaldehyde,

'acetaldehi de, benzaldehyde, butyraldehyde,

. tral condensate) the condensation product of acetaldehyde with ortho or para-toluidine, etc., the condensation product of furfuraldehyde with ammonia or with anilin or orthotoluidine, etc.- The condensation product of certain aldehydes and amines can be carried out either with or without an acid condensing agent, and the condensation product may be different in the diflerent cases. When an acid condensing agent is used, it maybe considered that the amine is used in the form of its salt, but when after the condensation the product is neutralized with caustic soda, the salt forming group will be removed. The condensation product may nevertheless in such case be different from that produced when no acid is used. Various amines, both aromatic and aliphatic, can be used for the condensation, as well as various alde'hydes.

tempering or heat treatment of metals, comprislng oils having combined therewith a I small amount of a condensation product of an aldehyde with a nitrogenous base.

3. Improvedheat treatment b ths for the tempering or heat treatment of metals, coinprising oils having combined therewith a small amount of a condensation product of an aldehyde with an amine.

4. The improvement in heat treatment of metals, which comprises immersing the metal in an oil composition and reducing objectionable decomposition of said composition and prolonging its useful life byincorporating therein a small amount of. a condensation product of a nitrogenous base with a carbonyl compound.

5; The improvement in the tempering or heat treatment of metals, which comprises immersing the metal in an oil composition and reducing objectionable decomposition of said composition and prolonging its useful life by incorporating therein a small amount of a condensation product of anitrogenous base with a carbonyl compound.

6. The improvement in the tempering or heat treatment of metals, which comprises immersing the metal in an oil composition and reducing obj ectionable decomposition of said composition and prolonging its useful life by incorporating therein a small amount of a condensation product of a nitrogenous base with an aldehyde.

In testimon whereof I aflix my signature.

A BERT A. SOMERVILLE.

- In a similar manner,-condens ation products of ketones and nitrogenous bases can be used,for example, condensation products of acetone with ammoma,'etc.

In using the new stabilized oil compositions, they ma be heated to the temperature at which such aths are commonly heated for tempering or heat treating purposes, and the metals can be immersed therein and heated thereby, or in the case of highly heated metals, may be cooled and quenched thereby. The

presence in the oil'bath of the stabilizing ma- ,terial will impart thereto improved stability against deterioration by atmospheric oxidation, as well as other improved properties,

thereby prolonging the useful life of the bath before it needs to e discarded and replaced.

I claim:

1. Improved heat treatment baths, for the tempering or heat treatment of-metals', comprising oils having. combined therewith a small amount of a condensation product of a carbonyl derivative with a nitrogenous base. 

